A heart valve prostheses crimping apparatus and method for deducing the diameter of stents containing heart valve prosthesis. A medical prosthesis catheter loading apparatus, including a crimping assembly for reducing the diameter of a prosthesis； and a catheter clamp for holding a catheter adjacent to the prosthesis. Also disclosed is an apparatus for reducing the diameter of a medical prosthesis, including a base, a crimp head connectable to the base, and an actuation mechanism connected to the base and connectable to the crimp head to actuate the crimp head. Also disclosed is a method of loading a medical prosthesis into a catheter, including the steps of reducing the diameter of a prosthesis from its normal deployed state to a diameter less than that of the lumen of the catheter； holding a catheter adjacent to the reduced diameter prosthesis； and moving the prosthesis into the catheter lumen. The following attorney's file identification forms no part of the disclosure or claims of this application.
